The long-term objectives of this research is to develop improved permanent soft denture lining materials suitable for clinical applications. In Phase I, the physical properties of the new materials were studied as functions of material formulations. Hardness, elongation, tensile strength, tear strength, bonding strength to denture base polymers, water sorption and solubility, the leaching of monomers from the cured specimen, the capability of the new materials to inhibit the growth of Candida albicans, and the polishability of the cured materials were investigated. In Phase II, the optimization of the material formulation and processing methods will be further investigated. Both clinical prosthesis fabrication processes and polishing techniques for the new lining materials will be developed. Clinical prostheses will be fabricated using the nearly optimized materials and processes, and clinical serviceability of the new lining materials will be evaluated and compared with the control Molloplast-B. PROPOSED COMMERCIAL APPLICATIONS: Potential commercial applications of the research is the development of improved soft denture lining material which have permanent resiliency, good bonding to the denture base polymer, low water sorption and solubility, and are suitable for clinical applications.